Grinding instrument for use in dental work



Feb. 22, 1938. H. P. COUSSEMENT ET AL 2,109,036

GRINDING INSTRUMENT FOR USE IN DENTAL WORK Filed May 15, 1936 jmvenZors.

///L A m: P. COUSSEMEN 7' FL oe/s 641 577:

Patented Feb. 22, 1938 UNITED STATES PATENT QFFIQE GRINDING INSTRUNIENT FOR USE IN DENTAL WORK Application May 15, In France 2 Claims.

The present invention has for its object the provision of an improved grinding instrument for use in dental work, and is characterized by its composition and by the provision of a novel mounting device.

There have hitherto been used for dental work and in the making of dentures, grinding discs of various shapes and sizes, but these grinding discs have usually been made of hard material and have proved unsuitable in that they attacked the enamel of the teeth and on the least contact therewith they destroyed this enamel and consequently considerably diminished the resistance of the teeth.

There have also been used supports upon which were arranged caps made of glass paper but such supports served only for polishing and it was impossible, on account of their delicate structure, to use them for roughing and finishing work.

According to the present invention, a grinding instrument is formed of a special composition and of any desired shape, the composition of which is such that the material which constitutes this instrument is not as hard as the enamel of the teeth which it cannot consequently attack whilst the said material is harder than the usual products such asz-hardened rubber, ebonite, synthetic resin or other similar materials used in the construction of dentures, and which permits the working of these materials easily without risking in any way damage to the enamel of the teeth.

The annexed drawing shows diagrammatically by way of example, one particular embodiment of the grinding instrument having the characteristics of the invention, in whichz-Fig. 1 is a. sectional view of a grinding instrument on its support, Fig. 2 illustrates one constructional form of the support and Fig. 3 illustrates a mount fitted on a milling spindle.

One method of producing a grinding instrument according to the invention is as follows:-

There is used for its manufacture crushed and pounded glass, reduced to sufficiently fine dimensions. The degree to which the glass may be powdered depends on the type of grinding wheel required for example, finishing or roughing grinding wheels, having finer or coarser grains respectively.

The binder may be any binding agent well known in the manufacture of grinding wheels, provided that the hardness of the binder used is less than that of the glass. For example, there may be chosen sodium silicate and there may be added thereto, in order to facilitate the forma- 1936, Serial No. 79,974 May 17, 1935 tion of the grinding apparatus, materials already known in the manufacture of foundry cores, such as gumlac or the like, so that the grinding apparatus may have, even before baking, a certain consistency.

There may also be provided the addition of colours to the mixture so as to permit the rapid differentiation of grinding apparatus of different granular structure.

The plastic mixture is moulded in known manner on the supports of the grinding apparatus and is then baked in a stove at a suitable temperature.

The grinding parts come out perfectly hard, well shaped and ready for use.

One particular form of grinding block is illustrated in Fig. 1, and consists of a cylindrical body terminating in a slightly conical portion. This grinding block is mounted on a support which is constituted by a part having on the outside a thread similar to that employed for wood screws. Alternatively circular grooves may be provided to enable the fixing of the grinding block on the support.

The interior of the block is formed as a conical hole having threads or grooves similar to those on the support for the purpose of mounting the grinding block on the spindles.

The supporting piece is preferably made of soft metal, such, for example, as an alloy of lead and antimony, similar to that of printing characters, or in a white alloy of the same nature.

Illustrated in Figure 3 is a mount fitted on a milling spindle as generally used by dental surgeons.

This mount is formed of a cylindrical portion identical with that at the extremity of the milling instruments and on this cylindrical end is fixed by any known means, for example, by soldering, a conical screw made of hard material such as, for example, steel, the angle of which screw at the top is the same as that of the inner cone of the grinding block supports. This part is screwed within the grinding block support, which is formed of softer material, in the direction of rotation of the milling spindle, with the result that a firm arrangement due to the well known clamping properties of an extended cone within a cone is obtained.

The grinding block is removed in exactly the same manner as a. milling tool. Several grinding blocks having different shapes or grain as desired, may be provided and each may be mount ed by its fixing pin on to the milling spindle.

The invention permits of working rapidly on the materials which constitute the dentures of even of carrying out certain dental surgical operations Without risk of injuring the enamel.

Naturally the shapes of the grinding blocks, their colour, the details of execution and moulding and the methods of utilization may vary Without departing from the scope of the present invention.

We claim:

1. In a grinding tool, a heat-baked head including a, metallic support and comprised of a mixture of comminuted glass, sodium silicate binder, and a temporary gum-lac binder carbonized during the baking of the head, said charred mass being uniformly distributed in the head to lower the resistance of the baked binderv 2. A milling tool of the character described, comprising a support of relatively soft metal of conical shape and provided with an exterior thread of variable pitch, said support having a smooth conical aperture for mounting on a spindle, and a head integrally mounted over said support, said head being constituted of a comininuted glass aggregated with a baked. silicate binder through which are uniformly distributed carbon particles originally of an organic nature and serving as a temporary bond for head-shaping purposes.

HILAIRE P. COUSSEMENT. F. CAPPE'I'IE. 

